MCQ
Statement A (Assertion): $\cos ^2 A-\sin ^2 A=1$ is a trigonometric identity.
Statement R (Reason) : An equation involving trigonometric ratios of an angle is called a trigonometric identity, if it is true for all values of the angles involved.
  • A
    Both assertion (A) and reason ( $R$ ) are true and reason $(R)$ is the correct explanation of assertion $(A)$.
  • B
    Both assertion (A) and reason ( $R$ ) are true and reason $(R)$ is not the correct explanation of assertion (A).
  • C
    Assertion $(A)$ is true but reason $(R)$ is false.
  • Assertion (A) is false but reason $(R)$ is true.

Answer

Correct option: D.
Assertion (A) is false but reason $(R)$ is true.
(d) : We have, $\cos ^2 A=\sin ^2 A=1$ Put $A=45^{\circ}$ we pet,
$
\cos ^2 45^{\circ}=\sin ^2 45^{\circ}=\left(\frac{1}{\sqrt{2}}\right)^2-\left(\frac{1}{\sqrt{2}}\right)^2=0 \neq 1
$
$\therefore$ It is not trigonometric identity.
$\therefore \quad$ Aseertion is talce but Reason is true.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : $\text{HCF}$ of two no. is product of no.$ \div$ their $\text{LCM}.$
Reason : Product of $\text{HCF}$ and $\text{LCM}$ of two no. is equal to product of two number.
Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : $\sqrt{5}$ is an irrational no.
Reason : The square root of every positive integer is always irraational.
Directions: In the following questions, a statement of assertion $(A)$ is followed by a statement of reason $(R)$. Mark the correct choice as:
Assertion: There is no such point or $X -$ axis which are at a distance $c ( c <3)$ from the point $(2,3)$.
Reason: The distance between two points $\left( x _1, y _1\right)$ and $\left( x _2, y _2\right)$ is $\sqrt{\left( x _2- x _1\right)^2+\left( y _2- y _1\right)^2}$
Statement $A ($Assertion$)$ : Point $P\left(1, \frac{5}{2}\right)$ is equidistant from the points $A(-5,3)$ and $B(7,2)$.
Statement $R$ (Reason$)$ : If a point $P$ is equidistant from the points $A$ and $B$, then $\text{AP=BP}$.
Statement A (Assertion) : The system of equations $3 x-y-5=0,6 x-2 y-k=0$ has no solution if $k=10$.
Statement $R$ (Reason) : The pair of equations $a_1 x+b_1 y+c_1=0$ and $a_2 x+b_2 y+c_2=0$ has no solution if $\frac{a_1}{a_2}=\frac{b_1}{b_2} \neq \frac{c_1}{c_2}$.
Directions : In the following questions, the Assertions $(A)$ and Reason $(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : The graph of linear polynomial intersect the $x -$ axis at point.
Reason : For polynomial $P(x)$ of degree n the graph of $y = P(x)$ intersect $x -$ axis at most points.
Directions: In the following questions, the Assertions $(A)$ and Reason$(s) (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: $(2+\sqrt{3})^{2}$ is irrational.
Reason: $(a + b)^2 = a^2 + b^2+ 2ab.$
Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : The largest number that divide $70$ and $125$ which leaves remainder $5$ and $8$ is $13.$
Reason : $\text{HCF}\ (65, 117) = 13.$
Directions : In the following questions, the Assertions $(A)$ and Reason $(s) \ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following :
Assertion : Irrational $+$ irrational $=$ irraational.
Reason : $\frac{\text{Integer}}{\text{Integer}}=\text{integer}.$
Statement-1 (A): If $\sin A=\frac{1}{3}\left(0^{\circ}<A<90^{\circ}\right)$, then the value of $\cos A$ is $\frac{2 \sqrt{2}}{3}$.
Statement-2 (R): For every angle $\theta, \sin ^2 \theta+\cos ^2 \theta=1$.